Array modifier fit curve option( curve direction problem(already Ctrl+A applied, but failed to fix)
It works better when you use the Curve modifier.

1) Go to Edit mode and rotate your mesh 90 degrees so it aligns better with the curve.
2) Set array modifier to Count or Length
3) Add a Curve Modifier and set the target to your curve.  

Rotate your mesh in edit mode.


Set Array modifier to Count and add a Curve modifier


Voilà!

And here is the edited file.